Omron V500-R521B2 User Manual page 120

Modulus check
This is a method to increase bar code reading reliability.
Numerical character or character obtained by specific calculating formula is applied to
the end of the data you want to express (also expressed as C/D: check digit in this
manual).
After reading a barcode, check the C/D with this calculating formula to avoid reading
failure. General check systems are the following three types.
System
Modulus 10/3 Used for barcodes with only numbers. Mainly used for EAN and ITF.
Modulus 43 Used for barcodes including alphabet. Mainly used for CODE39.
Modulus 16 Mainly used for NW-7.
Calculation method of modulus 10/3 weight
1.
Add the digits in the even positions (the rightmost character is the 1st digit), and
multiple it by 3.
2.
Add up the odd numbers (excluding the rightmost check digit) in the data digit.
3.
Add values of above clauses
4.
The check digit is the reminder of 10 minus first digit of clause
[E.g.] When the bar code data is 4901234 (JAN-8)
4 9 0 1 2 3 4
Even digit 4
Odd digit 9
30 + 13 = 43 (1st digit is 3)
10 - 3 = 7•••Check digit
Therefore, data with check character is "49012347".
1 2
and , and add to the unit digit.
+ 0 + 2 + 4 = 10 10 x 3 = 30
+ 1 + 3 = 13
Used barcode
3
.
Section 6
Appendix
V500-R521B2/C2
123
User's Manual